Overview of Spherical Torus Studies

Spherical torus is an advanced magnetic confinement device for nuclear fusion research,which retains many features of tokamak configuration,such as closed magnetic surfaces and field lines of medium rotational transform,and good plasma confinement.In addition it has low aspect ratio and lower toroidal magnetic field,and it is compact,economical with respect to traditional tokamak. Therefore it has the potential for a nuclear fusion reactor. Present paper the engineering,experiment, and theory status as well as challenges in spherical torus research are comprehensively presented in this paper.